Electronic discharge device



June 8, 193 7.

V. L. HOLDAWAY ELECTRONIC DISCHARGE DEVICE Filed May 2 2 Sheets-Sheet l lNl/ENTOR KLHOLDAWAY Br ATTORNEY June 8, 1937. v. HOLDAWAY 2,083,330

ELECTRONIC DISCHARGE DEVICE 2 Sheets-Sheet 2 Filed May 2, 1935 FIG. 5

FIG. 7.

lNl/E/VTDR By M LHOLDAWAK ATTORNEY atented June 8, 1 937 AENT orricr ELECTRGNIC nisonsnos DEVICE Application May 2, 1935, Serial No. 19,380

8 @laizms.

This invention relates to electronic discharge devices for rectifying alternating current and particularly for rectifying the complete cycle of the alternating current wave.

An object of the invention is to confine the ionization paths to a limited space between the electrodes and to prevent arcing and breakdown in the device.

Another object of the invention is to assemblethe electrode units in devices so that the internal impedance is relatively low to obtain efficient operation.

In accordance with this invention, a full wave rectifier comprises an assembly in which two symmetrical hollow anodes are mounted on a stem or a vessel and form complete enclosures for the cathodes or electron emitters which are supported laterally within the anodes by vertical supports extending into the anodes from one end. The configuration of the emitters insures large emitting surfaces to obtain a high efficiency in operation and also to reduce the internal impedance between the respective electrodes.

A feature of the invention is to prevent direct passage of electrons out of the anode spaces by forming baflle shields adjacent the apertures through which the supports extend.

A further feature pertains to the alignment of the cathode sections within the anodes to insure 3 stability in the characteristics of the device. This is accomplished by maintaining the relation. of the cathode sections to the anodes substantially constant by a restraining m mber which engages an intermediate portion of the cathode and is secured to one of the cathode supports, the member being coated with an insulating ceramic to avoid conduction to a support held at a difierent potential.

A further feature of the invention relates to the support of the electrode units in an enclosing vessel and the maintenance of uniform space relationship of the anodes without the use of spacers of insulating material. This arrangement comprises two anode casings supported from the stem of the vessel with the cathode supports entering twin apertures in the lower closure members of the anodes and spacing the two units in the vessel by similarly shaped tripodal members which are individually attached to the supports of the anodes. The spaced arms of the spacer members resiliently engage the wall of the vessel to prevent shocks or vibrations afiecting the relationship of the electrodes.

These and other features of the invention will be described in the following detailed specification and in connection with the accompanying drawings set forth various embodiments of the invention.

Fig. 1 is a perspective View of one embodiment of a full wave rectifier device in accordance with this invention with a portion of the enclosing vessel broken away to show the electrode unit assembly;

Fig. 2 illustrates a side view in elevation of one of the electrode units with the anode casing in cross-section to show the cathode assembly mounted therein;

Fig. 3 is similar to Fig. 2, but illustrates a modified arrangement of the. cathode structure;

Fig. 4 shows a cross-sectional view of theunit taken on the line 4-4 of Fig. 3;

Fig. 5 is a perspective view of another embodiment of the invention with a portion of the enclosing vessel and one of the anodes broken away to show the detail assembly of one of the dual L line 1-4 showing the relation of the anodes and spacer members with respect to the wall of the enclosing vessel.

Referring to the drawings, one aspect of the invention, as shown in Fig. 1, is a complete double half-wave rectifier device employing mercury vapor or other vapor as the ionizing medium, although a suitable inert gas or. a gaseous mixture may be used, and comprising an enclosing vessel l6 having an inwardly projecting stem H terminating in a flat press l2, the stem-end of the vessel being aifixed to an insulating base l3 having a plurality of terminal pins or prongs I4 and i5 projecting from the lower surface to which the separate electrodes are connected so to be coupled to an operating circuit. 7

The stem i2 is provided with two upright supports or rods l6 and I! having short portions thereof adjacent the press surrounded by glass insulating sleeves i8 and I9 respectively. The glass sleeves may be secured to the-stem by fusing the ends thereof into the press l2 during the sealing of the support rods I6 and I1. In order to maintain the support rods l5 and I! in uniform parallel relation, a spacer member or disc 2%, of mica or a suitable ceramic material, is secured to the extreme ends of the support rods in a conventional manner, such as by metallic eyelets 2!. The disc 20 is provided with a central elongated slot. 22, to increase the surface insulation path between the support rods l6 and I1. The disc is also provided with serrated edges 23 which engage the inner wall of the re-, duced end of the vessel It to maintain the electrode unit accurately in position with respect to the axis of the vessel. Two flattened cylindrical anodes 24 and 25 are arranged in parallel relation between the upright supportsifi and i1. Each anode is formed of sheet metal, such as nickel, and may be provided with a roughened or darkened surface, such as a'carbonized coating, to dissipatethe heat more readily and to decrease the possibility of a disturbing electron emission from the anode. 'The longitudinal edges of the anodes are brought together in the form of an outwardly extending fiange 26 which is welded to one side of the support rods 16 and I1, respectively. The top ofeach anode is provided with a metallic insert or closure 21 having an upwardly bent extension 28 which is welded to the inner edge of the anode. The lower ends of the hollow anodes are closed by insulating plates or closure members 29 and 30 having a slightly larger dimension than the cross-section of the anode associated therewith. The insulat ing plate 29 is held in abutting'relation to the anode'24 by a wire connector 3| and a similar connector 32secures the insulating plate 30' in abutting relation to the anode 25.; These connectors consist of a hairpin shaped wire, as shown in Figs. 2, 3 and 4, threaded through tight fitting holes adjacent the outer edge of the insulating plate'and having the parallel ends pro-' jecting through the plate bent outwardly and welded to the support rods 16 and I1, respectively; Each of the insulating plates is provided with twin apertures 33 and 34 along the long diameter of the plate and substantially at equal distances from the, center of the plate. The assembly of the anodes presents a pair of completely enclosed casings, due to the closure members at the top and bottom openings, and the-only passageways connecting the space within the anodes between the anodes and-the press I2. ,l The anode casings form enclosures for parallel cathode sections which are arranged in the axis of each anode casing, to serve as a source of electrons between the cathodes and the surrounding surface of the respective anodes. The cathode may be of any suitable configuration, and, as shownin Fig. 2, comprises a preformed folded ribbon 35, preferably of wire meshwhich is coated with electron emissive material, such as'the oxides of alkaline earth metals, preferably barium and strontium oxides. In order to main-' tain the cathode sections in properspacial relation with respect to the surfaces of the anodes, a U-shaped wire support- 36is attached to a bent wire 31 fastened in the press l2 and is provided with long arms 38 and 39 which project. through the apertures 34in the insulating plates 29 and 30. These arms extend almost to the upper 010- f V V the twin apertures in the insulating plates at the lower end of the anodes through which the sure members 21 of the anodes and carry extension stub Wires 40 which are attached to the upper ends of the cathodes to maintain'the centeror axis of the folded ribbon cathode 35- along the axis of the anode inwhich it is situated; The lower ends of the cathodes35 are secured to stublwires 4 [which extend from straight supports or conductors "41 and 43 projecting through the apertures 33 in the insulating plates center point of the cathode 35.

sealed in the press f2 and connected to corresponding leading-in conductors or wires 46 and 41, respectively, which are secured to the contact pins l4 on the base 13. The contact pins [5 are attached to leading-in conductors 48 and 49 which are joinedto the sealed ends'of the upright supports; and I1, respectively, to supply suitable potentials to the anodes of the rectifier device;

When a folded form of filament is employed in the rectifier device or any other form of cathode is employed which does not have sufficient rigidity to maintain it in uniform space relation with respect to the wall of the anode casing, it may be desirable to' provide an intermediate restraining member for the cathode assembly to insure constant spacing of the cathodes. As shown in Fig. 2, a wire hook 50 projects at right angles from the arm 39 extending into the anode casing and is provided with a loop portion 5| which endbraces the intermediate portion of-the cathode .by' a U-shaped wire 53 which extends through the block and is welded to the arm, such as 39, above and below the block. The block carries an offset pin-or bar 54 which is welded to the The bent arm or Wire 31, shown in Fig. 1, which carries the U- shaped support 36 for the cathodes also forms a support for a mesh container 55 containing a capsule'of mercury which forms the vapor conducting substance in the device. A getter ring 7 V 56 'is also supported'from the bent wire 31 by a to the surrounding .media are thegtwin aperj turesj33 and 34in the insulating'plates supported connecting wire 51.

The use of mercury'vapor in a rectifying device.

materially decreases the cathode-anode-voltage drop whereby a high output current may be obever, the maximum efficiency of such a combination is partially destroyed by arcing and breakdown between the supports of the dual assembly tained with a given electrode assembly. Howwhere these supports are joined by materials which may establish conducting paths between them.

In accordance with this invention arcing is materially decreased in the structure previously described by limiting the ionization paths to the supports of the cathode extend. a

In order to provide complete shielding of the 1 cathodes, in accordance Withthis invention, the

,twin apertures are masked by bafile shields 58" which are'in the form of tubularmetallic eyelets secured to" the individual arms 38' and 39 and the; short supportsfland 43 whichca'rry'the cathode 7 sections. These shields are providediwith flaredportions 59 which are spaced slightly above the apertures in the insulating plates 29 and 39 and the diameter of the flared portion is larger than the apertures in the plates so that any electrons projected from the cathodes cannot pass through the apertures into the surrounding Vapor by a direct path. In. view of the fact that any electrons striking the flared portion of the shield will be deflected to the anodes, it is obvious that ionization of the vapor exterior to the anode structure is substantially overcome. This arrangement materially increases the efilciency of the full wave rectifier and permits the attainment of a maximum peak inverse voltage without the danger of arcing.

In the embodiment of the invention as shown in Fig. 5, the dual unit assembly of the electrodes is attained without the use of insulation except for the supports extending through the stem of the device. In this arrangement the anodes 5B and 6! are in the form of hollow cylinders of sheet metal, such as nickel, with their edges joined together in a flange 62 and terminating in a U-shaped longitudinal groove or flute 63, which embraces the respective upright supports l6 and [1 extending from the press l2. The parallel anodes extend at acute angles from the press [2 on opposite sides thereof, as shown more clearly in Fig. 6 and are provided with upper metallic disc inserts 64 having a peripheral flange welded to the inner edges of the cylindrical anodes. The lower ends of the anodes are closed by metallic disc inserts 65 having twin apertures 66 and 51 so that each anode structure forms a substantially closed metallic casing. A central support 58 extends from the stem and carries the U-shaped frame 36, similar to the frame described in connection with Fig. l, but having the long arms 38 and 39 at a greater distance from the center of the frame and supported at a bisecting angle with 40 respect to the press !2 so that the arms 38 and 39 extend through the apertures 66 in both anodes 50 and GI. The folded ribbon cathode 35 is secured to the upper end of the arm by the stub wire 40 and the lower end is connected to the stub wire 4| which extends from the corresponding straight supports 42 and 43 projecting through the remaining apertures 61 in the lower inserts 65. The straight supports 42 and 43 are connected respectively to bent conductors 69 and i0 sealed in the press I2 and connected to the respective leading-in conductors 45 and 41. The twin apertures in the lower inserts of the two anodes are shielded by the tubular shields 58, similar to the structure described in connection with Fig. 2, and the intermediate points of the cathodes are restrained by insulated hooks 50. The mesh container 55 supporting the mercury capsule is supported from the center support 68 by a connecting wire H while the getter ring 56 60 is supported from the U-shaped frame 36 by a connecting wire 12. It will be realized that the electrodes are assembled in proper relation from the stem of the vessel without the aid of any spacing insulating member so that the insulation resistance between the separate units is materially increased and a higher degree of eificiency may be obtained.

In order to properly support the upper ends of the anodes of the rectifier device and also to overcome displacement of the anodes due to shocks or vibrations, another feature of this invention relates to the support of the separate units at the top of the vessel by individual tripodal resilient springs or spacer members which are posi- 7 5 tioned in superimposed relation transverse to the axis of the vessel and each spring has three points in contact with the wall of the containing vessel l0.

' It'will be noted that the upright support I! in Fig. 5 is slightly longer than the support I6 arranged parallel thereto. The upright support H has its free end secured between parallel portions of a hairpin-shaped wire section l3'so that the nodal portion is in contact with the cylindrical wall of the dome-shaped portion of the vessel ll]. Beyond the parallel portions of the hairpin section of the spring are angular legs l4 and which extend at equal angles from a diametrical point opposite the nodal portion of said spring and the ends of the legs are bent inwardly to present a rounded contact to the wall of the vessel iii at triangular points with respect to the bend of the hairpin section 13. This spring or spacer positions the support I! at its upper end and prevents vibrations or shocks altering the position of the support. A similar symmetrical spring or spacer is oonnected to the upright support It and is provided with a hairpin section 16 having the nodal portion in contact with the cylindrical wall of the vessel at a position diametrically opposite the nodal portion of the hairpin section 13. The angular legs l1 and 18 extend at opposed angles with respect to the legs 14 and '55, as shown clearly in Fig. '7, and the ends of these legs are bent inwardly to form a smooth contact with the inner wall of the vessel Ill. This arrangement maintains the dual sets of elements in position in the vessel and protects the assembly against shocks. Furthermore, the superimposed relation of the tripodal springs prevents the establishment of conducting paths between the two units and thereby increases the insulation resistance of the device. It will also be noted that the resilient character of the tripodal springs permits the spacer members to compensate for variations in the internal diameter of the vessel due to the yielding contact of the legs of the springs with the wall of the vessel.

While the invention has been described with respect to a dual rectifier device, it is, of course,

understood that the invention is not limited to such a specific application since other uses may be advantageously realized from the disclosure and concept of the invention. Furthermore, it is understood that the invention is not limited to a structure having a combination of the features disclosed since under certain conditions the operating characteristics of the device may be sufficiently improved by employing only one or more of the various features and therefore the invention should be defined within the scope of the appended claims.

What is claimed is:

1. A full wave rectifier comprising a vessel having a stem, a pair of parallel uprights extending from said stem, a spacer member attached to said uprights, a pair of hollow metallic anodes attached to and extending between said uprights in parallel relation, each of said anodes having closure members at opposite ends thereof, the closure member adjacent said stem having apertures, a plurality of supports extending into said anodes through said apertures, a pair of cathodes extending between pairs of said supports within said anodes, and flared members surrounding said supports adjacent said apertures.

2. A full wave rectifier comprising a vessel having a stem, a pair of parallel uprights extending from said stem, a spacer member attached to said uprights, a pair of hollow metallic anodes atparallel relation, each ofsaid anodes having clotached to and extending between said uprightsin sure members at opposite ends'thereof, the closure member adjacent said stem having apertures, a plurality of supports extending into saidanodes through said apertures, a pair of cathodes extending between pairs of said supports within said anodes, and tubulareyelets secured to said supports within said anodes having flared portions facing the apertures in said closure member adjacent said stem. i

3. A full wave rectifier comprising a vessel having a stem, a pair of parallel uprights extending from said stem, a spacer member attached to said uprights, a pair of hollow metallic anodes attached to said uprights in parallel relation, each of said anodes having a metallic closure over one of the corresponding ends thereof, a pair of apertured insulating plates abutting against the opposite ends of saidanodes, a pair of supports ports closely adjacent the inner surfaces of said insulating plates. 7 r 4. A full wave rectifier comprising a vessel having a stern, a pair of parallel uprights extending from said stem, a spacermember attached to said 30 uprights, a pair of hollow metallic anodes attached thereof, a pair of apertured insulating plates abutting against the opposite ends of said anodes, a pair of supports extending freely through each of said apertured insulating plates, a cathode extending lengthwise between each pair of said supports within each anode, metallic eyelets secured to said supports having portions shielding the apertures in said insulating plates, and means connecting the outer portion'of each of said insulating plates to the corresponding uprights.

5. A dual electrode assembly comprising a vessel having a stem, two similarc'athode and anode units, supported from said stem, and a tripod spacer member'connected to each of said units and engaging the wall of said vessel.

6. A dual electrode assembly comprising a vessel having a stem, two similar cathode and anode units supported from said stem, and a separate metallic spring spacer element engaging each unit and the adjacent wall of the vessel and hav ing symmetrical outwardly extending leg portions engaging other portions of the wall of said vesjsel at substantially equal angles from a diametricalpointopposite the engagement of said spacer element with the wall of said vessel.

7. A full wave rectifier comprising an enclosing vessel having a stem, a pair of uprights projecting from said stem, a pair of hollow anodes secured to said uprights, metallic inserts closing the open ends of said anodes, the insert adjacent said stem having twin apertures, supports extending from said stem and passing freely through the twin apertures, an electron emitting cathode within each of said anodes and supported by the respective supports passing through the twin apertures, and flared shielding members individually secured'to said supports adjacent said apertures. V

8. A full wave rectifier comprising an enclosing vessel having a stem, a pair of uprights projecting irom said stem, a pair of cylindrical anodes secured to said uprights, said anodes having upper I and lower closure portions, said'lower closure por-' tion having twin apertures, a ,U-shaped support extending from said stern and having an arm projecting into each of said anodes through one of each of said twin apertues, arfolded ribbon cathode within each anode having one end adjacent the upper closure portion connected to the correspondingarm of said U-shaped support, a pair of short supports extending from said stem and projecting through the remaining apertures in said lower closure portions and connected to the other ends of the respective cathcdes'wit hin said anodes, a pair of metallic spring spacers having triple arms mounted transversely beyond said anodes, each spacer having the similar arm slidably contacting with spaced portions of the wall of said vesselandthe intermediate arm secured to one of said uprights and also contacting'with a portion of the wall ofsaid vessel, and metallic shields 'securedto said support arms and short I supports and having flared portions substantial-- 

